MOLECULAR SIMULATION OF THE PROPERTIES OF GAS-ABSORPTION ON THE SURFACE OF NANOCRYSTALLINE TIO2

Molecular simulation techniques are employed here to study the surface properties of nanocrystalline TiO2. Monte-Carlo method (1) is used to predict the properties of gas absorption on the surface of TiO2. The interaction energies between gas molecules and TiO2 surface are calcul ated by the theory of open force field (2). The atomic model of TiO2 i s created by a 6 x 6 x 6 superlattice unit cell of rutile phase with a 15% facetting in {110} planes. CO, H2S, NO2 gases are chosen as react ing gases in this study. The molecular simulations are conducted under the temperature of 473, 573, 673, 773, 873K and the pressure of 0.1, 0.5. 1.0 kPa. The results indicate that the interaction energies betwe en gases and TiO2 surface can be used to predict the selectivity and s ensitivity of reacting gases in TiO2. (C) 1997 Acta Metallurgica Inc.